IRF6 and orofacial cleft: To date, studies have reported the association between more than 43 genes and loci with nonsyndromic orofacial clefts such as risk loci at chromosomal regions 1q, 9q, 16p12.1, 17q22 and others [74,75,76,77,78] and variants in susceptibility genes involved in craniofacial development such as IRF6 gene [78], MAFB [79], MAX1 [80] and TGFA [81].